In order to achieve finer wiring, higher density and high reliability of a substrate when manufacturing a semiconductor package substrate, a semi-additive process using plating for forming a conductor was suggested, and is being actively applied.
However, a copper etchant composition in a conventional semi-additive process had a change in etching properties, such as an increased metal content in the etchant composition (the increased number of processing sheets) as an etching process proceeds, or reduced etching rate and etching uniformity with increased processing time, which resulted in a fault phenomenon, such as non-uniform etching of a copper seed layer, and causing a residue.
Accordingly, there is currently a continuous demand for development of a copper etchant composition having excellent etching uniformity, and no change in etching properties depending on the number of processing sheets and etching time.
In the semi-additive process, sulfuric acid/hydrogen peroxide-based (Japanese Patent Registration No. 4430990), hydrochloric acid/cupric-based (Japanese Patent Laid-Open Publication No. 2006-111953), and hydrochloric acid/ferrous-based (Japanese Patent Registration No. 3962239) copper etchants have been suggested, as a copper etchant used for removing a copper plating film which is a seed layer.′